Field of the Invention
The present invention relates to a novel formulation of 1-(4,6-dimethoxypyrimidin-2-yl)-3-(3-ethylsulfonyl-2-pyridylsulfonyl)urea (rimsulfuron) with an anti-hydrolysis agent, to processes for its preparation and to its use in agrochemical preparations.
Description of Related Art
1-(4,6-dimethoxypyrimidin-2-yl)-3-(3-ethylsulfonyl-2-pyridylsulfonyl)urea (Rimsulfuron) is a potent herbicide having high selectivity, high efficiency, low toxicity, and other desirably attributes. Rimsulfuron has a molecular formula of C14H17N5O7S2. Its chemical structure is:

It is used post-emergence on crops, such as maize and potatoes, against a variety of annual and perennial grasses and broadleaved weeds. As may be expected for a selective herbicide, rimsulfuron can be highly toxic to some non-target plants, including duckweed, but it is rather less toxic towards algae and is of generally low toxicity towards most other wildlife.
Rimsulfuron, like other agricultural chemicals, can be formulated as concentrates in a variety of different formulations. However, when it is dissolved and dispersed in water, rimsulfuron can undergo significant hydrolysis. Furthermore, hydrolysis can occur during storage, particularly where the compound becomes exposed to moisture. As a result, the stability of rimsulfuron is of great concern.
U.S. Pat. No. 5,516,750, which is incorporated herein by reference for all purposes, describes the use of substituted isoxazolines as safeners to reduce phytotoxicity to plants for classes of pesticides, especially for post-emergent (tankmix) application of a safener-herbicide combination to the area under cultivation. The use of substituted isoxazolines as anti-hydrolysis agent has not been mentioned and exemplified.